It has been a while for me, so I'm going through the math again, and putting it up here as a check.
I have some inductance I want to measure. I know the range, but not the value. I'll use a test rig something like this...
The measurements at this point are hypothetical, I'm going through the math. The 100Khz will be from an old function generator, I'll be setting the freq with my counter built into my DVM. The coils resistance is also measure with the DVM.
RL = 1Ω
R1 = 1KΩ
L = ?
Total reactance formula is:
Rt = SQR( (R1+RL)^2 + (2πLf)^2 )
Therefore
L = SQR( (Rt^2 - (R1+RL)^2) / (2πF)^2 ) , Total Reactance (Rt) is the unknown at this point.
Extrapolating VL,
VL = V1 - RL ( (Vt-V1)/R1 ) = 1V - (1Ω (2V/1KΩ)
RL is insignificant in this example, but that won't always be the case.
I'll have to come back on this post to edit it, as I work it out.
I have some inductance I want to measure. I know the range, but not the value. I'll use a test rig something like this...
The measurements at this point are hypothetical, I'm going through the math. The 100Khz will be from an old function generator, I'll be setting the freq with my counter built into my DVM. The coils resistance is also measure with the DVM.
RL = 1Ω
R1 = 1KΩ
L = ?
Total reactance formula is:
Rt = SQR( (R1+RL)^2 + (2πLf)^2 )
Therefore
L = SQR( (Rt^2 - (R1+RL)^2) / (2πF)^2 ) , Total Reactance (Rt) is the unknown at this point.
Extrapolating VL,
VL = V1 - RL ( (Vt-V1)/R1 ) = 1V - (1Ω (2V/1KΩ)
RL is insignificant in this example, but that won't always be the case.
I'll have to come back on this post to edit it, as I work it out.
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